The present invention relates to a display device which allows an image containing parallax information to be viewed three-dimensionally or which can perform a displaying operation on from one screen to a plurality of screens, a position adjustment pattern display program used in such a display device, a recording medium, polarized glasses, and a method of adjusting the position of a filter of the display device. More particularly, the present invention relates to a filter position adjustment pattern for displaying an optimal three-dimensional image or for performing a displaying operation on from one screen to a plurality of screens when a divided wavelength plate filter is mounted, and a method of adjusting the position of the filter.
Hitherto, various attempts have been made to provide technologies for presenting images three-dimensionally. In many fields, such as photography, movies, and television, methods for displaying images three-dimensionally have been studied and put into practical use. Methods for displaying images three-dimensionally are broadly divided into a method using glasses and a method not using glasses. In both of these methods, an image having binocular parallax is input to the left and right eyes of a viewer to allow the viewer to view three-dimensional images. Typical examples of the method using glasses are what are called an anaglyph method using red, blue glasses and a method using polarized glasses. Color separation methods, such as the anaglyph method, have many qualitative problems including a difficulty in color presentation and reduction in the field of view. The method using polarized glasses has problems such as the necessity of generally using two projection devices. In recent years, however, a method which allows a three-dimensional display using one direct-viewing display device has been proposed.
FIG. 24 schematically shows a three-dimensional image display device making use of the method using polarized glasses. A three-dimensional image display device 200 comprises a liquid crystal panel 201 and a divided wavelength plate filter 202 mounted to the liquid crystal panel 201. The liquid crystal panel 201 has a pair of transparent supporting substrates 204 and 206, which are formed between a pair of polarizing plates 203 and 207, and pixel liquid crystal sections 205 each having RGB pixels being formed between the pair of transparent supporting substrates 204 and 206. The divided wavelength plate filter 202 is provided at a surface of the liquid crystal panel 201, and has a structure in which separated wavelength plates 208 are disposed at, for example, every other line on one surface of a transparent protective substrate 209. The divided wavelength plate filter 202 is also called a μ-Pol or a micropolarizer.
In the three-dimensional image display device 200 having such a structure, linearly polarized lights from an even-numbered line and an odd-numbered line on a display screen are converted into lights that are orthogonal to each other by rotating the direction of linearly polarized light that has exited from the liquid crystal panel 201. In other words, the linearly polarized light from the liquid crystal panel exits unchanged from an even-numbered line, whereas, the linearly polarized light from the liquid crystal panel is converted into a linearly polarized light which is orthogonal to the linearly polarized light exiting from the even-numbered line by the divided wavelength plates 208 and exits from an odd-numbered line. By viewing the lights from the display device with glasses 210 in which polarization directions are orthogonal to each other, a right-eye image light is incident upon the right eye, and a left-eye image light is incident upon the left eye. By viewing the images with the glasses 210, it is possible to view full-color three-dimensional images without any flickering.
A three-dimensional display device which does not require a viewer to wear glasses as a result of effectively making use of a wavelength plate filter such as that described above has been proposed (see Japanese Unexamined Patent Application Publication No. 10-63199). In addition, the present inventor et al. have proposed a display device which performs a displaying operation on from one display screen to a plurality of screens as an example of a display device which effectively makes use of the above-described wavelength plate filter (see Japanese Unexamined Patent Application Publication No. 11-249593), wherein a system takes out predetermined original images by an image separation mechanism after displaying a combination of two or more images on one display surface which potentially has an image separation mechanism.
When the divided wavelength plate filter 202 is mounted in a display device comprising the liquid crystal panel 201, etc., the divided wavelength plate filter 202 must be reliably secured to locations corresponding to predetermined areas (pixel positions) of the display device. However, this is not easy to achieve, thereby giving rise to the following problems.
The first problem occurs when mounting the divided wavelength plate filter. Since the above-described display method uses the display surface by dividing it in accordance with predetermined areas, forming the divided areas as thinly as possible in the form of a nest is effective in providing resolution. In addition, since the pixels of the display surface having higher resolution are becoming more minute, a high-definition panel can be obtained, but it is very difficult to precisely secure a corresponding high-definition divided wavelength plate filter, which is produced in a separate process, in correspondence with the pixels of the predetermined areas.
Even in the case where the divided wavelength plate filter is successfully precisely mounted, since the filter is generally secured using resin or the like, the position of the divided wavelength plate filter tends to become shifted during the period in which it is being secured until the resin hardens even if the position of the divided wavelength plate filter has been adjusted once. In addition, various factors, such as heat and vibration during conveyance of the divided wavelength plate filter, often cause the position of the divided wavelength plate filter to be shifted. Further, due to manufacturing problems, in order to maintain the precision of the predetermined areas, a glass substrate is, in general, often used for the divided wavelength plate filter, so that its position is, in particular, shifted by its own weight. Still further, various durability conditions, such as deterioration of the fixing agent, may cause the divided wavelength plate filter to be shifted, so that, when the hardened resin is shifted, it is very difficult to correct the position of the divided wavelength plate filter afterwards. Therefore, the relatively expensive display panel becomes utterly useless.
In the three-dimensional image display method, the optimal position of disposing the filter is determined by the positional height of the eyes of the viewer viewing an image. Therefore, the position where the filter is previously secured is not necessarily the optimal position when an image is being viewed. FIG. 25 shows this situation. A display device 220 shown in FIG. 25 comprises a pixel section 223, which is interposed between transparent supporting substrates 221 and 222, and a divided wavelength plate filter 225. In FIG. 25, the optimal position of disposing the wavelength plate filter for a viewer at a viewing position a corresponds to the position of the wavelength plate filter indicated by solid lines, whereas the optimal position of the wavelength plate filter for a viewer at a viewing position β corresponds to the position of the wavelength plate filter similarly indicated by dotted lines. In this way, as is clear from FIG. 25, the optimal position of disposing the filter depends upon, for example, the positional height of the eyes of the viewer viewing an image as well as, for example, the angle of the monitor or the liquid crystal panel, so that the position where the divided wavelength plate filter is previously secured does not necessarily correspond to the optimal position of disposing the divided wavelength plate filter when an image is being viewed.
By any of the aforementioned factors, when the divided wavelength plate filter is shifted by a few percent to tens of percent (tens of μm in the example above) with respect to the pixels, the shift appears large as crosstalk between the pixels. When the divided wavelength plate filter is properly set, a light ray from the corresponding pixel always passes through the corresponding wavelength plate area, so that light rays from the pixels other than the corresponding pixel do not pass through the corresponding wavelength plate area. However, when the divided wavelength plate filter is tilted, even if the divided wavelength plate filter is only slightly shifted by an amount of the order of a few percent to tens of percent with respect to the pixel, and by an absolute value of, for example, of the order of 50 μm, the amount of shift in the vertical direction becomes large at both ends of the divided wavelength plate filter, so that there may be a portion of the light ray from the corresponding pixel that does not pass through the corresponding wavelength plate area. As a result, crosstalk between images occurs, so that proper three-dimensional images cannot be displayed.
Hitherto, in the mounting of the wavelength plate filter, a composite image for three-dimensional display similar to the usual composite image has been displayed on a screen, and a viewer wears polarized glasses and views the composite image to see whether or not it actually appears as a three-dimensional image in order to determine the position of the divided wavelength plate filter. However, the standard for determining whether or not the image appears as a three-dimensional image is very unclear, so that there is a demand for making it possible to position the divided wavelength plate filter using a more accurate method.
Accordingly, in view of the aforementioned technological problems, it is an object of the present invention to provide a display device which allows an image containing parallax information to be reliably viewed three-dimensionally even when a divided wavelength plate filter is mounted, or a display device which can reliably perform a displaying operation on from one display screen to a plurality of display screens, polarized glasses used in such display devices, and a method of adjusting the position of the filter of the display device.